TL084: how to decide the maximum input common mode voltage

Hi Yangbo,

the typical maximum peak output voltage for different supply voltages is given in figure 6 of datasheet: For a supply voltage of +/-10V the maximum peak output voltage is about +/-8.7V, a 10k load assumed.

And section 6.3 of datasheet says that the common mode input voltage should stay 4V away from the rails. So, for a supply voltage of +/-10V the recommended common mode input voltage range is +/-6V.

Kai

Yangbo,

I think Kai has fully answered your questions.

For the input common mode range, section 6.3 should be used.  You will notice that this section's common mode input voltage range corresponds with the minimum specification given in section 6.5, as shown in your post.

Here is the second figure referred to by Kai.  Note that figures 1 - 6 all have relevant information on the output voltage range.  So, you may find these useful as well.

Finally, there is a PSpice model available online for simulation, if needed.  Please let us know if you have any remaining issues.

Regards,

Daniel